Department of Internal Medicine III, University Hospital of Cologne, Kerpener Str. 62, D-50937 Cologne, Köln, Germany.
Cardiovasc Res. 2013 Dec 1;100(3):432-40. doi: 10.1093/cvr/cvt213. Epub 2013 Sep 16.
Induced pluripotent stem cell-derived cardiomyocytes (iPSCM) are regarded as promising cell type for cardiac cell replacement therapy. We investigated long-term electrophysiological integration and maturation of transplanted iPSCM, which are essential for therapeutic benefit.
Murine iPSCM expressing enhanced green fluorescent protein and a puromycin resistance under control of the α-myosin heavy chain promoter were purified by antibiotic selection and injected into adult mouse hearts. After 6-12 days, 3-6 weeks, or 6-8 months, viable slices of recipient hearts were prepared. Slices were focally stimulated by a unipolar electrode placed in host tissue, and intracellular action potentials (APs) were recorded with glass microelectrodes in transplanted cells and neighbouring host tissue within the slices. Persistence and electrical integration of transplanted iPSCM into recipient hearts could be demonstrated at all time points. Quality of coupling improved, as indicated by a maximal stimulation frequency without conduction blocks of 5.77 ± 0.54 Hz at 6-12 days, 8.98 ± 0.38 Hz at 3-6 weeks and 10.82 ± 1.07 Hz at 6-8 months after transplantation. AP properties of iPSCM became more mature from 6-12 days to 6-8 months after transplantation, but still differed significantly from those of host APs.
Transplanted iPSCM can persist in the long term and integrate electrically into host tissue, supporting their potential for cell replacement therapy. Quality of electrical integration improves between 6-12 days and 6-8 months after transplantation, and there are signs of an electrophysiological maturation. However, even after 6-8 months, AP properties of transplanted iPSCM differ from those of recipient cardiomyocytes.
诱导多能干细胞衍生的心肌细胞（iPSCM）被认为是心脏细胞替代治疗有前途的细胞类型。我们研究了移植的 iPSCM 的长期电生理整合和成熟，这对于治疗益处至关重要。
表达增强型绿色荧光蛋白和嘌呤霉素抗性的小鼠 iPSCM 在α-肌球蛋白重链启动子的控制下表达，并通过抗生素选择进行纯化，然后注入成年小鼠心脏。在 6-12 天、3-6 周或 6-8 个月后，制备受者心脏的存活切片。通过放置在宿主组织中的单极电极对切片进行局灶性刺激，并在切片内的移植细胞和邻近的宿主组织中用玻璃微电极记录细胞内动作电位（AP）。在所有时间点都可以证明移植的 iPSCM 在受者心脏中的持久性和电整合。随着最大刺激频率的增加，耦合质量得到改善，没有传导阻滞，在移植后 6-12 天为 5.77±0.54 Hz，在 3-6 周为 8.98±0.38 Hz，在 6-8 个月为 10.82±1.07 Hz。AP 特性从移植后 6-12 天到 6-8 个月变得更加成熟，但仍与宿主 AP 有显著差异。
移植的 iPSCM 可以长期存在并与宿主组织电整合，支持它们作为细胞替代治疗的潜力。在移植后 6-12 天和 6-8 个月之间，电整合的质量得到改善，并且存在电生理成熟的迹象。然而，即使在 6-8 个月后，移植的 iPSCM 的 AP 特性仍与受者心肌细胞不同。
